net2890 ETC-unknow, net2890 Datasheet - Page 19

• Manufacturer Part Number: net2890
• Description: Interface Controller
• Manufacturer: ETC-unknow

Specification
4.5.1.1 Control Write Transfer
A successful control write transfer to Control Endpoint 0 consists of the following:
Setup
Data (zero, one
or more packets)
Status
During the Setup transaction, the NET2890 stores the data stage packet in its Setup Registers. The
NET2890 returns an ACK handshake to the host after all 8 bytes have been received. A Setup Packet
Interrupt status bit is set to notify the local CPU that a setup packet has been received. The 8-byte data
packet is then read and interpreted by the local CPU. A Setup transaction cannot be stalled or NAKed, but if
the data is corrupted, then the NET2890 will not return an ACK to the host.
During the Data transaction, zero, one or more data packets are written into the Endpoint 0 FIFO. For each
packet:
For a successful Status transaction, the NET2890 returns a zero length data packet. A NAK or STALL can
be returned if an error occurred.
____________________________________________________________________________________
Transaction
Interrupt status bits are set and can interrupt the local CPU
The local CPU reads the FIFO
The NET2890 returns an ACK if no error has occurred.
Setup Token
Data
Status
OUT Token
Data (1/0)
Status
IN Token
Data
Status
Stage
335 Pioneer Way, Mountain View, California 94041
TEL [phone] FAX [phone]
NetChip Technology, Inc., 1999
Rev 2.0, Draft 9, July 16, 1999
SETUP PID, address, endpoint, and CRC5
DATA0 PID, 8 data bytes, and CRC16
ACK
OUT PID, address, endpoint, and CRC5
DATA PID, N data bytes, and CRC16
ACK
IN PID, address, endpoint, and CRC5
DATA1 PID, zero length packet, and CRC16
ACK
http://www.netchip.com
Packet Contents
NET2890 USB Interface Controller
# of bytes
N+3
11
3
1
3
1
3
3
1
NET2890
NET2890
NET2890
Source
Host
Host
Host
Host
Host
Host
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